This invention relates to a method and a phase converter utilizing a reference alternating voltage Eo and producing a regulated phase-displaced voltage E.phi. of same frequency and same modulus, and having a common point with said reference voltage, the ratio of the phase-displaced voltage to the reference voltage being represented by a ratio of two complex conjugate numbers having each in relation to a reference axis an argument equal to one-half of a desired phase displacement angle, whereby the phase-displaced voltage can be considered as resulting from a sum of two voltages of which the first voltage V.sub.1 is equal to the reference voltage Eo but has its sign inverted and the second voltage V.sub.2 is equal to twice a third voltage V.sub.3 delivered from a common point to a capacitor and a resistor of an impedance circuit comprising at least said capacitor and said resistor connected in series.
This type of phase converters, sometimes referred to as "pure delay phase converters", is well known and notably described in a book entitled: "The operational amplifier and its applications" by J. C. Marchais, 1971, published by Masson & Cie., Page 95. These known phase converters utilized notably in the French Patent Application No. 2,017,210 filed on Sept. 1, 1969 by N. V. Philips Gloeilampenfabrieken comprise an amplifier having two inputs so that none of them is grounded directly. Due to the interaction between the two inputs of this amplifier the degree of precision of the gain and of the phase displacement angle cannot exceed 0.1% under the most exceptional conditions.